In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric frac...In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric fraction and asphaltene is great. The interfacial pressure of fractions increases in strongly basic conditions. The ζ (-80mv) of acid fraction is the largest under basic conditions (pH=11-12), with the result to show that the interfacial activity of the acid fraction is superior to that of other fractions. The results of model emulsions show that strongly basic conolition (pH≥11) is beneficial to oil-in- water emulsion stability. The interfacial activity of acid fraction and asphaltene is superior to that of other crude fractions.展开更多
One of the important characteristics of pulsar radiation is polarization.It is considered not only as a probe for recognizing the structure of a magnetic field,but also as a lighthouse for estimating spacecraft attitu...One of the important characteristics of pulsar radiation is polarization.It is considered not only as a probe for recognizing the structure of a magnetic field,but also as a lighthouse for estimating spacecraft attitude via orientation information between the pulsar and the detector.Although polarization of a pulsar has been studied for decades,until recently applications to determination of spacecraft attitude have been seldom reported.This paper deals with analysis of the feasibility of applying polarization information to attitude estimation.The stability factor(SFR) and observation fluctuation factor(OFR) are introduced to analyze the stability of a pulsar's polarized position angle.Based on European Pulsar Network(EPN) data,several simulated instances are used to demonstrate that the accuracy requirement of attitude determination can be met via polarization measurement.The SFR of a pulsar is evaluated using simulated polarization data,and the OFR is used to analyze the relationship between fluctuation extent and observation time.Simulation results show that the polarized measurement of candidate pulsars PSR B0470-28 and PSR B2319+60 reaches the specification for attitude determination.展开更多
文摘In this paper, effects of pH on the interfacial properties of heavy crude functional fractions and water system are investigated. The influence of pH on π-A isotherms of acid fraction, basic fraction, amphoteric fraction and asphaltene is great. The interfacial pressure of fractions increases in strongly basic conditions. The ζ (-80mv) of acid fraction is the largest under basic conditions (pH=11-12), with the result to show that the interfacial activity of the acid fraction is superior to that of other fractions. The results of model emulsions show that strongly basic conolition (pH≥11) is beneficial to oil-in- water emulsion stability. The interfacial activity of acid fraction and asphaltene is superior to that of other crude fractions.
基金Project supported by the National Natural Science Foundation of China(No.61172318)the Fundamental Research Funds for the Central Universities,China(Nos.K5051302015 and K5051302040)
文摘One of the important characteristics of pulsar radiation is polarization.It is considered not only as a probe for recognizing the structure of a magnetic field,but also as a lighthouse for estimating spacecraft attitude via orientation information between the pulsar and the detector.Although polarization of a pulsar has been studied for decades,until recently applications to determination of spacecraft attitude have been seldom reported.This paper deals with analysis of the feasibility of applying polarization information to attitude estimation.The stability factor(SFR) and observation fluctuation factor(OFR) are introduced to analyze the stability of a pulsar's polarized position angle.Based on European Pulsar Network(EPN) data,several simulated instances are used to demonstrate that the accuracy requirement of attitude determination can be met via polarization measurement.The SFR of a pulsar is evaluated using simulated polarization data,and the OFR is used to analyze the relationship between fluctuation extent and observation time.Simulation results show that the polarized measurement of candidate pulsars PSR B0470-28 and PSR B2319+60 reaches the specification for attitude determination.
